Bought a Dell XPS M1530 in late 2008. This past Christmas it started acting very strange, at first only successfully booting on the second 'power on', then every fifth, tenth, 20th, etc.. Long story short I got up the nerve to take apart a laptop and replaced the motherboard with a new one from ebay (warranty was long expired).

The current problem:

After many hours of carefully putting it back together, i hit the power button and it booted up fine!!! I was so proud until i touched the keyboard and BAM, black screen and all of a sudden it's going through the boot process. It turns out that every time I bump the thing, even with only enough force to squash an ant, this crash happens.

Here's the strange thing - it only happens when I have a stick of ram in the second DIMM slot. The ram itself seems fine. The computer boots up a-ok with either stick in the first dimm, and I can basically beat the snot out of the computer and it merrily continues computing. As soon as I boot with the ram in the second dimm, I can recreate the problem every time.

Clearly this is a hardware problem, but what would cause the thing to reboot ONLY when ram is slotted into a certain dimm? I've checked closely and when it's installed, it's in there all the way and it's not moving when it gets jolted. I've tried it running with just the battery, plugged into the AC adapter, with both sticks of ram in every combination - I'M STUMPED. 20 years of tinkering with hardware and I'm still running into problems that have me scratching my head...